JavaScript applications consist of statements with an appropriate syntax. A single statement may span multiple lines. Multiple statements may occur on a single line if each statement is separated by a semicolon. This isn't a keyword, but a group of keywords.

Iterations

Creates a loop that executes a specified statement until the test condition evaluates to false. The condition is evaluated after executing the statement, resulting in the specified statement executing at least once.

Iterates over iterable objects (including arrays, array-like objects, iterators and generators), invoking a custom iteration hook with statements to be executed for the value of each distinct property.

Notes Prior to Firefox 44, let is only available to code blocks in HTML wrapped in a <script type="application/javascript;version=1.7"> block (or higher version) and has different semantics (e.g. no temporal dead zone).

Notes Prior to Firefox 46, a TypeError is thrown on redeclaration instead of a SyntaxError.

Notes Prior to Firefox 44, let is only available to code blocks in HTML wrapped in a <script type="application/javascript;version=1.7"> block (or higher version) and has different semantics (e.g. no temporal dead zone).

Notes Prior to Firefox 46, a TypeError is thrown on redeclaration instead of a SyntaxError.